Reentrant condensation transition in a model of driven scalar active matter with diffusivity edge

Abstract

The effect of a diffusivity edge is studied in a system of scalar active matter confined by a periodic potential and driven by an externally applied force. We find that this system shows qualitatively distinct stationary regimes depending on the amplitude of the driving force with respect to the potential barrier. For small driving, the diffusivity edge induces a transition to a condensed phase analogous to the Bose–Einstein-like condensation reported for the nondriven case, which is characterized by a density-independent steady state current. Conversely, large external forces lead to a qualitatively different phase diagram since in this case condensation is only possible beyond a given density threshold, while the associated transition at higher densities is found to be reentrant.

Collective synchronization of dissipatively-coupled noise-activated processes

“…Of great interest would also be the interactions between non-identical oscillators, as only the synchronization between identical oscillators has been studied so far. Lastly, one may explore connections to Bose-Einstein-like condensation in driven scalar active matter [52] when interactions among particles are non-negligible.…”

Dynamic control of the Bose–Einstein-like condensation transition in scalar active matter

“…At this point, we want to stress that condensation can be achieved either by tuning the effective temperature T eff , similar to previous research [6,7,9], or by evolving the system in time, with a suitable (time-dependent) potential. Hence, there exists both a critical temperature T c and a critical time t c to condensation.…”

“…At condensation, the ground state density reaches the threshold ρ 0 (T c ) = ρ c , which corresponds to f(t, T eff ) = f(t, T c ). Note that for general potentials U(r) the condensate need not be formed solely at the position of the local minimum, but can instead occupy a finite width [9].…”

“…Introducing an external driving force into the periodically confined system was shown to lead to qualitatively distinct stationary regimes depending on the amplitude of the driving force with respect to the potential barriers [9]. For small external forces, the condensation transition was shown to be qualitatively similar to the transition induced by harmonic confinement [6], while large forces lead to a reentrant transition, depending on the average density, where the condensation transition is accompanied by a low-temperature evaporation transition.…”

“…The key to understanding the rich phenomenology of active systems lies in the formulation of minimal models that capture the essential physics [1,5]. Recently, a class of such active systems, distinguished by a diffusivity edge inducing condensation at steady states, has emerged as a generic mean field description for density-dependent diffusivity, in which some mean field dynamical features are represented [6][7][8][9]. This diffusivity edge, characterised by a critical density threshold beyond which particle mobility vanishes, introduces a unique and intriguing facet into the dynamics of scalar active matter.…”